The affinity of MCF7 breast cancer cells to hyaluronan substrates of different molecular weight and concentrations in an in vitro model

The affinity of MCF7 breast cancer cells to hyaluronan (HA) was investigate d in an in vitro model. The cells form a tightly adhering monolayer on nati ve HA with a concentration of 5 mg/ml. On native HA at higher concentration s the cells reduce their adhesion to the substrate in favor of increased in tercellular bonds, resulting in a clusterlike aggregate that tends to detac h from the substrate. Aggregate formation is accomplished after 12 h incuba tion. The phenomenon is independent of the CD44 receptor. Degradation of na tive HA by hyaluronidase abolishes aggregate formation even at high HA conc entrations in favor of formation of a firmly adhering monolayer. This model may help to understand tumor spread on HA tissue structures and may explai n therapy successes with hyaluronidase in tumor patients.